This invention is concerned with the surfaces of metals and metalloids and particularly relates to a method of detecting and measuring and/or comparing chemical and physical characteristics of such surfaces and with apparatus for performing such a method.
It is known that no two objects, whether they are natural or artificial, are idential in all respects. In at least some one or more respects, they differ. The differences may lie in shape, size, color, internal structure, chemical composition, both internal and external, and other items. In many cases, means exist for determining and/or comparing such differences. However, except for such easily determined differences as those in color, reflectivity and roughness or smoothness, no means has been available until now for detecting and measuring the differences in the surfaces of metals and metalloids resulting from internal stresses and surface chemistry variations. The last mentioned differences may be caused by, among other factors, differences in cooling rates, localized heating, mechanical treatment and environmental factors.
Since the behavior of a metal in many uses, such as electroplating, adhesive bonding, and deep drawing, for example, is affected by its surface characteristics, it is important to be able to detect differences in such characteristics and determine, i.e. map out, the areas affected. With metalloids, also, surface differences are in some cases important and the determination of the degree of difference and/or the area involved are desirable.